Love the story! Congrats on the group. I would love to make a roadie to Big sky country to shoot with you. There are some sweet chuck spots in Montana I've been told. We don't need lots of chucks, just one that's really FAR off!
I agree with Shawn on several of his comments. We shoot at 1500 yard chucks in one place in Idaho over a huge canyon and it always is funny to watch the thermals come up out of the canyon and toss your bullet 5 feet higher from shot to shot!
I also agree with Shawn on the ogive length and meplat uniformity. On our range the other day, the ogive length was causing the bullets to change velocity about 50 fps because of the longer bearing surface on some. We were sitting there on the bench and watching the chronograph as we shot at 2000 yards. Every shot that was 25 feet faster would land about a minute and a half higher! We also noticed some that dropped way down below the gong but remained the same velocity! There was no down drafts that we could tell, so it must have been the bad meplats on the MKs. Read this: www.davidtubb.com/tcom_images/reloading/bmu_one.html
I ordered a BMU from Kevin Cram yesterday and I will let you know how it affects 2000 yard shooting on or about the 20th of March.
There is one other thing that you might be interested in. After reviewing the tape of our shoot, I began to notice that the bullets that landed right usually also landed low, and the bullets that went left usually always landed high. Then it dawned on me that I had read about this before and had just forgot about it in the excitement of the day. It is called the Magnus effect. You may already know this, but I will explain it for others who don't. This phenomenon is not gyroscopic drift which is a more common term. Magnus has to do with the rotation of the bullet in relation to the winds current direction. It is explained wonderfully in the book, "precision shooting at 1000 yards" on page 116-117.
Here is the scenario:
No wind. You hold center bull, and you hit dead center. Now there is a wind from the right to left. You know that if you hold dead center again, the bullet will impact slightly to the left. So you hold (or click) into the wind the correct amount and fire. The bullet hits center but <font color="red">high! </font> You are shocked, but think it was just a fluke and shoot again. But now, the wind is coming from left to right. So you outsmart the wind and hold (or click) left into the wind the correct amount and fire. You hit dead center, but it hits <font color="blue">low!</font> Ok, what happened. It is Magnus! It is simply a phenomenon that takes place because a right-to-left wind pushes a right-handed twisted bullet left and high, and a left-to-right wind pushes the same bullet right and low! And the farther out you shoot, the worse this thing gets. At 100 yards, it is about half a bullet diameter in certain conditions. At 2 grand, it could be 20 inches! Man this is technical, but it sure is fun!